1. Field of the Invention
This invention relates to floor care machines, such as vacuum cleaners, which have a working head which is positioned on the floor surface when the machine is in use. The working head of a vacuum cleaner generally includes a rotating brush, a suction blower and a motor for operating both the brush and the blower. In addition, this working head also generally requires a spacing device, such as a wheel for guiding the vacuum cleaner and controlling the proper spacing between the working head and the floor.
2. Background Information
With the vacuum cleaner of the present invention, one motor is provided for operating the suction blower as well as the cleaning brush. The cleaning brush is driven simultaneously with the suction blower by means of additional drive devices such as drive belts. Since all of the heaviest components of the vacuum cleaner are mounted in the brush-suction head which rolls along the ground, the load that the user experiences may be kept particularly low.
On the other hand, this configuration therefore results in a heavier brush-suction head, which brush suction head is generally guided along the floor on a set of wheels. The wheels also generally provide the spacing between the brush-suction head and the floor so that a proper brushing of the floor is achieved. That is, depending on the height or pile of the carpet, the height between the brushes and the carpet can be adjusted so that the brushes contact the carpet with sufficient brushing action as the brushes rotate.
Wheels for such a vacuum cleaner also generally need to make it possible for the machine to be moved back and forth on the floor relatively easily. Typically, the wheels are made of a hard material, such as metal or hard plastic, and these types of wheels have significant disadvantages, particularly when they are run over hard floors, in particular stone floors with joints and seams. As such a device with hard wheels is run over joints or seams in hard floor, hard impacts are transmitted to the device, and these impacts generally result in relatively loud noises.
To achieve damping or suspension effects, of course, the prior art has equipped such machines with wheels which support a soft and elastic tire about the circumference of the wheels. However, it has been shown that satisfactory results can only be achieved with such a soft and elastic tire if the tire is relatively soft and thick. These soft and thick tire arrangements, however, result in excess wear of the tire, resulting in the frequent need for tire replacement, and the machine leaves streaks on the floor. Further, if the machine is allowed to sit idle for a long period of time, that is, with the same portion of the tire in continuous contact with the floor, permanent deformations of the tire occur, and these permanent deformations in turn, cause noisy and bumpy operation of the machine.
These disadvantages can of course be eliminated by a wear-resistant tire material which also resists permanent deformations. But, with such a wear-resistant tire arrangement, the tire cannot be sufficiently elastic, and therefore, when the tire is in contact over its entire surface with the roll body, or hub, the damping effect of the tire is very small.